In recent years, gaskets are used in hard disk drives (which may be hereinafter simply referred to as “HDDs”) of computers, recording devices, and the like, for dustproof purpose and for preventing entry of water vapor.
An easiest way to improve water vapor barrier properties (which may be hereinafter simply referred to as “barrier properties”) of a gasket is to increase the hardness of the gasket. However, since such a gasket is, in use, compressed by the members to be adhered or sealed, flexibility is also required from a durability standpoint.
Materials for ultraviolet-curable gaskets include epoxy acrylates, urethane acrylates, and the like (see, for example, JP2010-260918A (PTL 1), JP2009-43295A (PTL 2), and JP2009-221329A (PTL 3)).